Hello jac_84,
You have reached Microsoft Learning Support, who provide assistance with the Microsoft Certification program.
Since you are trying to change the sign in email address of your Microsoft Learn account, you may need to create a ticket to
Microsoft Learn support directly. Please see screenshot below:

In case that this is about your Microsoft Certification profile, in order to link your preferred Microsoft Account and password to your MCID, an access code must be generated. This can be done by unlinking
the old email address from your profile.
To locate and verify your account, please provide the information specified in the
private message initiated (please see below image).

Note that the access code is just a one-time use code.
I look forward to your response. Please note that if no response is received within two business days, the case will be closed and locked. After the case is locked, we will no longer be able to respond, even
through Private Messages. Thank you.
Regards,